Blake FriedmanandFacebook GitHub Bot
bfca23a25d
Summary:
Currently npx has a variety of caching strategies to avoid having to pull a version of the package from a registry. These are often unexpected to our users, who may fall behind. After looking at a variety of fancy approaches to dealing with this (the high end of which was intelligently forking npx to run `npx react-native@latest <args>`, the best possible tradeoff for time and simplicity was to warn the user when they weren't running the latest release:
{F999520817}
### Problem Details
On my laptop when you run `npx <package> <arguments>` this it eventually calls [libnpmexec](https://github.com/npm/cli/tree/0783cff9653928359a6c68c8fdf30b9fd02130c9/workspaces/libnpmexec), which applies this lookup [algorithm](https://github.com/npm/cli/blob/0783cff9653928359a6c68c8fdf30b9fd02130c9/workspaces/libnpmexec/lib/index.js#L39-L41) for `package@version`:
- is package available in local modules (npm root → `~/project/node_modules/<package>`)?. **Importantly it will walk all the way down to `/` looking for `node_modules/<package>`**.
- is package available in global modules (npm root -g → `/Users/blakef/.nvm/versions/node/v17.9.0/lib/node_modules`)?
- is package available in npx cache (`~/.npm/_npx`)?
- is package available in your registry? Download to the npx cache `~/.npm/_npx/<hash>/`
At this point you'll have a cached copy, which then has its bin script run with the arguments you originally provided.
### How this works against React-Native users
Users can get their development environment into a **persistent** pickle with a bunch of unintended side-effects of npx / npm exec’s caching model:
- **It matters where you run `npx react-native`**, since it’ll default to the version of react-native in a node package's folder. This works well for us in a React Native project, but not when initializing a project outside of a package folder.
- **Global and relative node_modules really matter**. If your users runs npx react-native init and they have a version of react-native installed globally, it’ll use that version.
- If the user has a `node_modules/react-native` installation anywhere in the directory hierarchy it’ll be used. For example if I run `npx react-native init Foobar` in `/home/blakef/src/example` , npx will look for versions of react-native like this before searching globals or the npx cache:
- /home/blakef/src/example/node_modules
- /home/blakef/src/node_modules
- /home/blakef/node_modules
- /home/node_modules
- /node_modules
**nvm just makes things harder** if your user switches between versions of node it can be hard to determine if they're affected by a globally installed version. Examples include having a `.nvmrc` file in the directory they run the command which transparently switches node version (and globals location).
## Changelog:
[General][Added] - Log a warning if npx react-native uses old cached version
Pull Request resolved: https://github.com/facebook/react-native/pull/37510
Test Plan: Ran this directly from the project, defining the `npm_lifecycle_event=npx` to mock directly running using `npx`.
Reviewed By: Andjeliko
Differential Revision: D46069419
Pulled By: blakef
fbshipit-source-id: 1c1af7f639c5312760a39a0828b89b7ddf2b5fda
React Native
Learn once, write anywhere:
Build mobile apps with React.
Getting Started · Learn the Basics · Showcase · Contribute · Community · Support
React Native brings React's declarative UI framework to iOS and Android. With React Native, you use native UI controls and have full access to the native platform.
- Declarative. React makes it painless to create interactive UIs. Declarative views make your code more predictable and easier to debug.
- Component-Based. Build encapsulated components that manage their state, then compose them to make complex UIs.
- Developer Velocity. See local changes in seconds. Changes to JavaScript code can be live reloaded without rebuilding the native app.
- Portability. Reuse code across iOS, Android, and other platforms.
React Native is developed and supported by many companies and individual core contributors. Find out more in our ecosystem overview.
Contents
- Requirements
- Building your first React Native app
- Documentation
- Upgrading
- How to Contribute
- Code of Conduct
- License
📋 Requirements
React Native apps may target iOS 12.4 and Android 5.0 (API 21) or newer. You may use Windows, macOS, or Linux as your development operating system, though building and running iOS apps is limited to macOS. Tools like Expo can be used to work around this.
🎉 Building your first React Native app
Follow the Getting Started guide. The recommended way to install React Native depends on your project. Here you can find short guides for the most common scenarios:
📖 Documentation
The full documentation for React Native can be found on our website.
The React Native documentation discusses components, APIs, and topics that are specific to React Native. For further documentation on the React API that is shared between React Native and React DOM, refer to the React documentation.
The source for the React Native documentation and website is hosted on a separate repo, @facebook/react-native-website.
🚀 Upgrading
Upgrading to new versions of React Native may give you access to more APIs, views, developer tools, and other goodies. See the Upgrading Guide for instructions.
React Native releases are discussed in this discussion repo.
👏 How to Contribute
The main purpose of this repository is to continue evolving React Native core. We want to make contributing to this project as easy and transparent as possible, and we are grateful to the community for contributing bug fixes and improvements. Read below to learn how you can take part in improving React Native.
Code of Conduct
Facebook has adopted a Code of Conduct that we expect project participants to adhere to. Please read the full text so that you can understand what actions will and will not be tolerated.
Contributing Guide
Read our Contributing Guide to learn about our development process, how to propose bugfixes and improvements, and how to build and test your changes to React Native.
Open Source Roadmap
You can learn more about our vision for React Native in the Roadmap.
Good First Issues
We have a list of good first issues that contain bugs which have a relatively limited scope. This is a great place to get started, gain experience, and get familiar with our contribution process.
Discussions
Larger discussions and proposals are discussed in @react-native-community/discussions-and-proposals.
📄 License
React Native is MIT licensed, as found in the LICENSE file.
React Native documentation is Creative Commons licensed, as found in the LICENSE-docs file.